Having successfully incorporated 8k poly asteroids into the game, I for one think that the polycounts are fine as long as that's the in-game polycount and not a quad count. People are still far too attached to the ultra-low poly levels, when in fact the engine is well beyond them. The big question is the number of textures, as that's what dominates performance.
As for the shadow ships, they are a little too vertically-oriented for shadows, IMHO, but that's really the only major flaw I see in them. And as TBP is running on a fighter sim, having more things to actually fly around against can't be a bad thing, can it?